Artificial foot



May 17, 1949. s, FQGG 2,470,480

ARTIFICIAL FOOT Filed April 23, 194s 2 Sheets-Sheet 1 Inventor ST :2 N LEY F: E-Er WW E May 17, 1949. s. R. FOGG 2,470,480-

' ARTIFICIAL FOOT I Filed April 23, 1946 2 Sheets-Sheet 2 Inventor STFINLEY I: BE-

y Attorneys Patented May 17, 1949 UNITED STATES PATENT OFFICE ARTIFICIAL FOOT Staniey R. Fogg, Terre Haute, Ind.

Application April 23, 1346, Serial No. 664,298

9 Claims. 1

This invention relates to an artificial foot and ankle construction by which is made available to the wearer, when pressure is exerted upon the foot portion thereof, all of the various actions, and particularly rectilinear actions, which is possible in a natural foot.

An object of the invention is to provide a novel relatively simple and light weight artificial foot, for permitting the natural action thereof, as in a natural foot, and which is provided with an ankle plate connected and supported relative to the sole portion, in such a manner as to give a spring cushioning and retarding effect similar to the movement of the foot at the ankle joint in a natural foot, and to compensate for the rectilinear action of the foot and angularly with respect to the leg at the ankle joint, which will raise the sole and toe of the foot or lower the same, in the progressive steps as in walking, and also to provide a novel joint and spring connection at the toe which will clear the toe of the ground, the same as in a human foot, as a step is completed and the weight of the body is removed from the back of the foot.

A further object of the invention to pro-- vide a novel pivot joint at the ankle and hydranlic spring cushioning means therefor in conjunc tion with an ankle plate to which the leg proper is connected, and also a novel ball and socket joint associated with a spring for connecting the pivoted toe section of the foot to the sole thereof at the back thereof, where it joins with the ball of the sole.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a perspective view of an artificial foot constructed in accordance with the invention.

Figure 2 is a side elevation partly in section at the ankle joint and cushionin means at the heel of the foot.

Figure 3 is a view similar to Figure 2 but with the leg portion abbreviated and showing the action of the parts when taking a step.

Figure 4 is an enlarged detail sectional elevation of the ankle joint pivot.

Figure 5 is a detail sectional plan view of the hydraulic cushioning control means, and

Figure 6 is a detailsectional elevation of the resilient connection between the sole and toe.

Referring to the drawings in detail, in which like reference characters designate corresponding parts throughout the several views, the improved artificial foot is shown as comprising a sole plate In having a heel portion H, an arch portion l2 and a toe portion [3. The toe portion !3 is hinged or pivoted transversely across the sole at its juncture with the ball portion of the latter by means of pivots l4 engaging apertured ears I5 extending upwardly from opposite edges of the ball portion of the sole at the transverse pivot connection by means of a flange i6 extending transversely the full width of the toe portion at its rear edge and formed at the outer ends thereof, with the pivot pins I 4, or vice versa.

The toe portion is provided with a raised tapered convex frame designed to fit the toe of a shoe, as indicated at H, and comprising a plurality of spaced longitudinal frame members or wires #8 of any suitable number, extending from the tip or rounded toe edge at the front and curved upwardly and rearwardly to join at their rear ends, as indicated at 19, to a transverse arched member 20 having its extremities curved downwardly and suitably anchored to the toe portion I3 as indicated at 2| as by riveting, welding, brazing, soldering or otherwise. The members l8 are spaced around the convex front edge of the toe portion [3 and correspondingly anchored at their front lower ends thereto in the same manner as the ends of the arch portion 2%), as indicated at 22 and progressively shorter from the center to the outside members. At the rear ends of the outside members [8, which are similarly connected to the arched member 20, a transverse rectilinear frame member 23 is provided with its ends anchored thereto at such points as indicated at 24 and forming the chord of an arc of the arch portion 20 beneath the latter, between said points.

An expansible coil spring or other resilient means 25 is interposed in an inclined position rearwardly from the center of the arched portion,

21} and connecting member 23 to the sole E0 in spaced relation rearwardly at the back of the toe frame I1, and may have its rear extremity 2t suitably anchored in an apertured ear or lug 2'5 secured centrally of the width of the sole on the ball portion thereof. The upper forward end of the expansible means or spring 25 is provided with a ball and socket connection with the toe frame permitting universal movement, and for this purpose, a hemi-spherical cup 28 is fitted or set in the forward end of the sprin 25 at the end coils thereof, and has a flanged top edge or rim 29 turned over the outside of the top coil or convolution of the spring to grip and retain the cup in position. The flanged edge of the cup extends beyond the point of the largest diameter thereof, to receive and retain a ball mem-.,-

ber 30 therein for angular movement, and has a two point connection with the toe frame I! by a multiple or pair of arms 3| rigid with the ball member and attached to the arched portion 20 and brace member 23 centrally of the lengths thereof and-'widthof the toe at. this point. The purpose of: this. arrangement is to give a round firm bearing surface for the collar supporting spring in order that the spring will remain in.

line at all times. At the same time, the toe pol.- tion I3 will be retained in rectilinear alignment with the sole portion and will be allowed the. necessary angular movement with respect, there-.

to, in walking, and permitting the rear portion of the artificial foot to move upwardly andedowtnr1 wardly relative thereto, as well as to cause the hinged .toe portion. to. align with. the. soleproperby, reason of the. joint andresilientmeans or springwhich. controls ,the same,-.-so-that; the I natural. recoil of the toe-asthefoot is lifted from the ground or at 'theecompletion ofma step, is attained...

A suitable leg portion .3.2cisshown: connected or pivoted-for angular movement with respect to the foot .portion at the'anklejoint. 33, and may comprise a; suitable-outer shell. or wall as shown, withinterior reinforcing-andliirame members or wires .34 bracing .thesame, inconnection with an ovate. or. .lenticularlongitudinally extending" ankleplate 3.5 at the-bottom. of the leg portion. For :this purpose,- the lower end of the leg portion at. the 1shell. andinterior reinforcing frame 34, is rigidly attachedgto thetop oithe ankle plate, in any suitable way.-,; as by riveting, welding, bracing, or otherwise.

Mounted: between the ankle 'plate- 35 andnthe heel of the sole is a;hydr,aulically controlled ankle joint or. pivot- 36. including:aicylindrical wrist pin.

31 mounted, in. a hinge or; sleeve comprising a central. section; 38, .welded: on otherwise-fixed tov the ankle .plate-35-.transyersely,. at apoint intermediate the lengththereof v asshown at:-39; and.

a pair of endsections lfi abuttingtheends of; the

central section. 3B-around the wrist pinor hingetlwith an interposed; fibre or, sound silencing. and cushioning-bushing 41 between the-sections and-the-pin. if desired. The sections ware supportedat an elevated: position: spaced above the heel portion of the sole-and,held-rig-idly-against turning, bya. suitableframestructure includ.-, ing spaced parallel-wvertical rods-42,.- forwardly inclined and divergent rods43 extendingto the side edges andfront. end of the sole plate=in rear.

of the The portion. I 3; and anchored thereto, with a transverse upwardly arched' intermediate connecting rods, 49.pivotallyconnected at 50..

by suitablebearing bracketsor. otherwise, to the bottomiace of the ankle plate 35.. The plungers are normally held. raised. by central .compression 4 springs 5| disposed between the pistons and the closed lower ends of the cylinders to give a desired degree of resistence and cushioning effect as well as upward movement of the cylinders in walking, during the angular movement of the foot and le portions relative to each other and under the weight of the person equipped with an artificial leg and foot. This resistence and cushioning effect is increased by springs 52 concentrioally encircling the springs 5| below the upper portionsof the latter and also resting on the closed lower ends of the cylinders, so that under the extreme weight of the body or pressure in walking, greater resistance is offered to the downward movement outwardly of the pistons or plungers MA. A suitable hydraulic fluid, such as oil, or air, within the cylinders and the flow thereof from one cylinder to the other at the bottom may be effected through the medium of a by-pass or duct 53 in the base plate 46 or other form of conduit connecting the lower ends of the cylinderchambers and controlled by a needle valve or, the like as operating in athreadedbore formed asa continuation of, the longitudinal" portion of the passage 53 at one end of-the base plate or other interiorly threadedwextensionthereof and adapted to beturnedby; a T-head orpin 55 or other form of-.- knob? or handle. so asto control the flow of the fiuidothroug-hithe passage-.53: at its vertical connection :Wi'tht the chamber-of: one

of thercylinders ll, preferably,--the-forward one-- at the tapered endof the valve.

By the construction described; the ankle jointor pivot. is. hydraulically controlled-but. preferablyalloweda full90 arc ofswing, while the -toe-por-.

tion at its hinged.connection .and'resilientlyor;

spring controlled as. described; is allowed a. maxi.-v mum swing in an arc-ofv Thus, in walkingproper angular. movements. are allowed; relatively betweenvthe leg portion.- 32 and the foot at. the ankle joint, and also.betWeemthe toeplatepand-- The twocompensating-hydraulic cylthe sole. inders or cushioning means between the-leg and thus the ankle plate-.and .the foot-plate or 501e,, automatically ladl'usts the position "of the "ankle plate with respect, to-the footlplate-at the-:ankle':

joint and to the position Which-1's.v natural to I the.

function-it .is'performing during the walking;

movement, so that at-each step,,-as pressure is. exertedupon the pistons, either-thefront-.01- rear.

pistons or plunger isdepressed, withincitscylinder; causing compression onits; respective springs-,

outward andinward.- strokes::respectively,-.- with the springs expanding or pressing .-against the/.-

pistons to maintainconstant, pressure between themand the foot plate orsolesorthat the. ankle-:1

movement is accomplished in a smooth and noise.-.: less 'manner. A150,. by having-the coil springs rest at. all times in.rubbers.cushioning-.;discs ;56. between the springs and the lower-endsofthe.

pistons: to. seal. theahydraulic "fiuid within; the; cylinders and from escaping. aronndlthelatterdandi;

between the same andthe-innenwalls of. .theicylr. inders, is prevented ..by-;. a..,simple .andv.. efficient form of packing. Thus,.as,.the .ankle plate tiltsh downwardly, in. front,. the. weight on the...body transmittedby. means of.- the framework .tolthe. toe,-. causes the-spring 25...-to.. be .-compress.ed. or coil;

elevating; the, planeof ,the-rear'. of. .the. sole-at. the ankleorhingedzjoint- 33,.asshowndnl'e'igure 3 of the drawings. As the weight is lifted, the spring 25 recoils, lifting the foot clear and permitting it to be swung forward to complete the step. On raising the foot from the ground, the spring 25 maintains the toe portion of the sole or foot plate I in alignment therewith as shown in Figures 1 and 2 of the drawings. Then, as the heel is set down, the action in the other cylinder by reason of the hydrauliccushion and spring action on the pistons, cushions the downward and rearward movement of the leg and foot at the heel, duplicating that of the forward piston in the first or initial stage of the step. This compresses the springs 5| and 52, until the foot is level on the ground, when the springs act uniformly tending to level the ankle plate 35 when the leg portion is vertical. This movement is cushioned by the resistance to the downward movement of the pistons by the fluid contained in the cylinder at the back, while pressing against the forward pistons, assisted by the action of the expansible springs therein. Adjustment of the needle valve controlling the passage of the fluid through the feeder tube or passageway produced by the duct 53, controls the volume of fluid passing into the respective cylinders on the opposite movement of the pistons therein, so that the walking action can be suited to the particular person and regulated to a nicety. This will also permit adjustment to compensate for the variations in the weight of different wearers.

Particular attention is called to the fact that the hinge flange which extends the full width of the toe plate or frame, swinging on the pin formed by the frame or ball portion of the sole plate it, of the body of the foot, insures positive alignment of the plate portions at their pivoted edges, the purpose of the hinged flange being to make possible the same spring reaction which clears the toe of a human foot as a step is completed and the weight of the body is removed from the back foot. It should also be noted that all mechanical parts are located below the ankle plate and are therefore arranged compactly to facilitate the movements as well as the construction and assembly of the device and all parts may be of steel tubular construction, including the framework, if desired, assuring maximum strength and minimum weight.

In view of the foregoing description taken in conjunction with the accompanying drawings it is believed that a clear understanding of the construction, operation and advantages of the device will be quite apparent to those skilled in this art. A more detailed description is accordingly deemed unnecessary.

It is to be understood, however, that even though there is herein shown and described a preferred embodiment of the invention the same is susceptible to certain changes fully comprehended by the spirit of the invention as herein described and the scope of the appended claims.

What I claim is:

1. In an artificial limb, the combination with a lower limb portion, an ankle plate secured thereto, a sole plate pivoted at a raised point to the ankle plate, hydraulic cushioning means between the ankle plate and the heel of the sole plate in front and rear of the pivot, and means for controlling said hydraulic means, a connection through which the fluid passes from one to the other, and means for controlling the passage of fluid through said connection.

2. In an artificial limb, the combination with a lower limb portion, an ankle plate secured thereto, a sole plate pivoted at a raised point to the ankle plate, hydraulic cushioning means between the ankle plate and the heel of the sole plate in front and rear of the pivot including cylinders mounted on the heel portion of the sole plate, plungers operating in said cylinders and having pivotal connection with the ankle plate, springs in said cylinders between the plungers and lower ends of the cylinders and cushioning the downward movement of the pistons in the cylinders, a passageway connecting the lower ends of the cylinders, a valve for controlling the flow of fluid through said passageway from one cylinder to the other, and a framework mounted on said sole plate.

3. In an artificial limb, the combination with a lower limb portion, an ankle plate secured thereto, a sole plate pivoted at a raised point to the ankle plate, hydraulic cushioning means between the ankle plate and the heel of the sole plate in front and rear of the pivot including cylinders mounted on the heel portion of the sole plate, plungers operating in said cylinders and having pivotal connection with the ankle plate, springs in said cylinders between the plungers and lower ends of the cylinders and cushioning the downward movement of the pistons in the cylinders, other springs in the cylinders and encircling the first springs to engage the plungers when forced downwardly, a passageway connecting the lower ends of the cylinders, a valve for controlling the ilow of fluid through said passageway from one cylinder to the other, a toe plate pivoted transversely to the sole plate, and resilient means connecting the sole plate, to the toe plate at a raised point thereon.

4. In an artificial limb, the combination with a lower limb portion, an ankle plate secured thereto, a sole plate pivoted at a raised point to the ankle plate, hydraulic cushioning means between the ankle plate and the heel of the sole plate in front and rear of the pivot including cylinders mounted on the heel portion of the sole plate, plungers operating in said cylinders and having pivotal connection with the ankle plate, springs in said cylinders and cushioning the downward movement of the pistons in the cylinders, a passageway connecting the lower ends of the cylinders, a valve for controlling the flow of fiuid through said passageway from one cylinder to the other, a toe plate pivoted transversely to the sole plate, and resilient means connecting the sole plate to the toe plate at a raised point thereon, said resilient means having a universal joint connection between it and the raised point of the plate.

5. In an artificial limb, the combination with a lower limb portion, an ankle plate secured thereto, a sole plate pivoted at a raised point to the ankle plate, hydraulic cushioning means between the ankle plate and the heel of the sole plate in front and rear of the pivot including cylinders mounted on the heel portion of the sole plate, plungers operating in said cylinders and having pivotal connection with the ankle plate, springs in said cylinders and cushioning the downward movement of the pistons in the cylinders, a passageway connecting the lower ends of the cylinders, a valve for controlling the flow of fluid through said passageway from one cylinder to the other, a toe plate pivoted transversely to the sole plate, a frame on the toe plate and extending transversely above the pivotal connection thereof with the sole plate, a spring anchored to the sole plate in rear of the frame, and a ball and socket connection lbetween the rearxofthe flame and the runner. ifOlZWEFd :end :of' thee-spring;

:6. In an artificial limb, Lthe combination.withv springs. :in :saideylinders and cushioning athedownward movement of "the. pistonsfinthe cy1 inrlers; a passageway connecting the IDWBI'QSHflS' of the cylinders, a valve for COIltIOllingftherflflW of .fiuidthrough said passageway from one; cylinderxto the other, a toe-plate pivotedwtransversely to the sole plate, a frame 1on2 thefcoe plate and extending transversely aboveithezpiw otal connection thereof with the sole plate, 1a-

spring anchored to the sole plate in sthelreanofthe frame, a cup mounted in the-upper portion:

of the spring" and having a flange engaging around the'upper .conv0lution.:of :the sp in a ball seated in said cup for :universal movement.

with the flange extending overthe ip0int0fj=131rg+ est: diameter thereof to ,retain the ball .in; thesocket, and a rigidtconnection between the :ball

and the-rearcof the toeiframe.

'7. An artificial foot including an ankle plate adapted for connection with the lower limb portion'of anartificial leg, -a horizontal;pivot.;.positioned centrally beneath the ankle plate a sole plate, a frame connectin the pivot torthesole. plate at a point spaced abovethel-heel of sole plate, cushioning means between ,the ankle plate.

andlthe heel. of the sole plate centrallyinfront and in rear of thepivot connection, artoe :plate pivoted at its rear edge transversely to the :sole. plate, aframe on the toe plate and terminating above the pivotal connection, and .a spring'con nected to the sole plate centrally and extending.

upwardly to the top of the frame at the rear thereof, and a universal joint connection between, the spring andthe rear of *the-toe-frame and rigid-' With the latter.

8. An artificial foot including an ankle plate adapted for connection with the lower limb portion of anartificiallega horizontal pivotuposh tionedcentrally beneaththe soleplate eta-point spaced above the heel of sole plate, cushioning means between the ankle plate and the heel of the soleplate eentrally in front and in rear of the ipivot connection, --'a toe plate pivoted at its rear edge .transversely to the sole .plate, .a frame on -the:toe;p1ate anditerminating ab'ovezthe pivotal connection, resilient-means connecting the frame: of the' toe plate to the heel plate at .a point spaced rearwardly therefrom, a base plate mounted ron the' heelhportionnof the sole plate, cylinders mounted in1 upright position on the base plate :and connected -by 'a passageway in' the base platezat'ethexlower ends :of the cylinders, pistonszmovablewertically in said cylinders ,and having pivotal connection -with1theankle plate infront'sand. irear oiffthezpivotzthereof, means for controllingv the passage of fluid- 'through said passagelfrom' one= cylinder r-to the other, and a pluralitymf: :cushionin springs in 'eachcylinder between-cthed'ower ends thereof :and the pistons, and ref different tensions, :to igiveivaried :cushioning action :to athe; pistons .inwalking.

'9. :An: zartificial dent :comprising a, flat .sole plate; cans-ankle 'p'la'te transversely zpivoted theretoicentrally between the front andzrear edgesof the::ankle plate; :cushioning means :between :the ankle gplate andthe: sole plate, a fiat toe plate portion pivoted:at:its'mear edgeitorthe front edge of" thezsole plate, qavraisedntbe frame on the toe plate;aand arcoil spring connectin the sole plate and the. raised toe frame of the toe plate at a point :elevated above :the :pivot of the latter to the soleplateto causeithe toe'plate'toalign with thersole'plate andclear the ground :as the step is H completed and the-weight :of "the body is removedzfrom the back font When walking.

STANLEY vR. vFOGGr.

"REFERENCES 'CITlED The following ireferences are-of record in the file o'f this patentz UNIIIED .S'IATES PATENTS Number .Name Date 92,03I Foster June 29, 1869 708,005: Baldwin Sept. 2, 1902 09,875 Wilkins J an. 9, 1906 11 ,076,861" Anvil Oct. '28, 1913 21127566 lBrehanoff Aug-23, 1938 FOREIGN PATENTS Number Country Date 523,329 :Flrance Apr. 19,1921 

